[Dan S]

Most people have probably seen reference to the study, some years ago, which suggested that drivers pass closer to cyclists who are wearing a helmet than they do to those who are not.  It’s often cited as a reason not to wear a helmet.

Without wanting to make an argument either way as to helmet use, I thought that some people might be interested in a further analysis of the same data (i.e. the researchers got hold of the raw data from the original experiment and looked at it again to see whether it was properly interpreted).  This study went into rather more depth, comparing a number of factors and considering their statistical significance rather than just drawing simple numbers.

Short version of the conclusions:

1. Yes, cars pass closer on average if you are wearing a helmet.

2. That only applies to cars passing more than 2m away.  Cars that give you 2m+ clearance will give an average 7cm more room to somebody without a helmet (2.27m v 2.20m).  

3. The overwhelming majority of passes took place 1-2m away.  They gave, on average, 1-2cm more clearance to those without a helmet (and this figure was not statistically significant).  Also not statistically significant were the figures for 0.5-0.75m passes (no difference) and less than 0.75cm (those wearing helmets were given 5cm MORE room – 66cm v 61cm).

4. Overall, since the only statistically significant increase is in passes at a good distance “these results do not support the idea that any substantive risk reduction can be gained from not wearing a helmet”.

5. The most significant correlations were actually road type (drivers on the “regular urban streets” of Bristol gave less clearance than those on the “residential” and “rural” roads of Salisbury) and distance to kerb (the further the cyclist was from the kerb, the closer the cars passed).  

 

As I said, not trying to argue one way or the other, but this study is often brought up and i thought it might be useful to see that it does not in fact support the proposition for which it is generally cited.  The full text of the reanalysis is here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3783373/

Topic

[Anthony.C]

I see what you did there..

I see what you did there..

[alansmurphy]

Do bright rear lights pass

Do bright rear lights pass closer if you wear a helmet?

 

[Anthony.C]

I would like to see a similar

I would like to see a similar study done for bright rear lights..

[Kapelmuur]

After reading the original

After reading the original research on the subject I did some testing of my own,  alternating bare headed and helmeted rides.

The result from my sample of 1 person is that it made no difference whatsoever.

What made drivers behave differently was road conditions.   If it was busy drivers would be less patient and make closer or riskier passes.   The opposite happened when the roads were quiet.

 

 

 

[brooksby]

I agree with others here that

I agree with others here that one of the reasons I wear a helmet (when I do) is because my wife spotted me going out the door and ordered me to get my helmet…

I used to wear a helmet religiously all the time, but I’ve had a few falling-downs over the last few years (black ice, black ice, dropped kerb, car door) and in none of them has my head been anywhere near the ground or my helmet in contact with the ground.  On all of them, its been my legs or ribs or arms which have been hurt, and I have no intention of starting to wear stormtrooper armour to ride my bike!

So, now I wear no head covering or just a cycling cap (unless I get caught going out the door!).  I haven’t noticed any difference in how I’m treated by other road users.  I’m not aware of being given more or less room than I was before.  But I will say it’s more comfortable not wearing a helmet, at this time of year…

(I appreciate that this is entirely anecdotal.  YMMV.)

[alansmurphy]

I am also against compulsary

I am also against compulsary wearing but wear one for the majority of my miles, and with stupid logic. When on a weekend or evening ride (20-100 miles) I ride one, as do all of our ‘club’; when i commute a couple of miles to work then i don’t. 

 

I suppose one (the leisure ride) is just part of the outfit; base layer, lycra, silly shoes, helmet et al and possibly peer pressure and/or the knowledge that I may attack a corner at 30+mph. The commute is something I have to do, another part of a busy morning and frankly I can’t be arsed.

 

Here’s the fail – commuting knock downs = 3; leisure = 0

 

 

[ChairRDRF]

Interesting discussion on

Interesting discussion on adaptive behaviour by OTHER road users to helmet wearing. Don’t forget adaptive behaviour to wearinga helmet (risk compensation) by the wearer themselves – see the discussion here

The effects of New Zealand’s cycle helmet law: The evidence and what it means.

[fenix]

I’ll sometimes induce a bit

I’ll sometimes induce a bit of a wiggle into my riding if cars are passing too close. 

 

If if they see you’re a competent rider and riding in a straight line some drivers will pass close. 

 

If you’re a little more erratic then you do get more room. But it’s a bit of a faff.

[Carton]

PennineRider wrote:

Something which I often wonder is…

You find an awful lot of anti-compulsion feeling on cycling forums, and an awful lot of “a helmet won’t really protect you” stuff, but when I’m out and about, the only cyclist I see without a helmet is me.

Each to their own, but where are all of the helmet-freedom campaigners? Maybe they’re all commuting in cities, rather than slogging it over t’moors…

…anyone?

I wear a helmet when riding for fun, I don’t when I’m commuting or going to the shops. When riding it’s not particularly inconvenient, it don’t find it significantly different than wearing a hat. Even on a transport ride, if it’s long enough I’ll put the lid on. What I dislike is having to log it around when walking. 

What I dislike even more are measures that reduce the amount of cyclists, and compulsory helmets certainly qualify.

And what I despise to no end is the victim blaming that oft follows when a cyclist not wearing a helmet is hurt or killed by a careless driver, based on the marginal chance that wearing a helmet might’ve helped. I can’t even imagine what that would be like if helmets were made compulsory.

[700c]

keirik wrote:

keirik wrote:

Helmet discussions are a waste of time, as you’ll always get people quoting statistics they don’t understand and extrapolating those stats to individual situations where they’re invalid, and they then descend into abuse of anyone who disagrees.

Exactly what he said.

[fukawitribe]

Bez wrote:

FWIW:

https://twitter.com/ianwalker/status/745606048652865537

His own analysis showed a similar point, look at his website.

[riotgibbon]

Daveyraveygravey wrote:

I don’t let drivers get away with close passing me, I always shout and gesticulate.  I have noticed that nearly always following cars then give an exaggerated amount of room.  Apart from the one that got especially close.

 

I find this, the upturned hand of despair (as opposed to the downward hand of warning) then seems to  result in the next lot giving more room. I assume that the driver behind then does think “ooh, that thing the car in front is actually a person), but who knows …. 

 

most drivers are fine in the first place, so perhaps it’s just the contrast

[davel]

PennineRider wrote:

Something which I often wonder is…

You find an awful lot of anti-compulsion feeling on cycling forums, and an awful lot of “a helmet won’t really protect you” stuff, but when I’m out and about, the only cyclist I see without a helmet is me.

Each to their own, but where are all of the helmet-freedom campaigners? Maybe they’re all commuting in cities, rather than slogging it over t’moors…

…anyone?

I’m in the anti-compulsion and generally anti-helmet camp, but I wear one on most rides.

Two reasons:

1. events demand it (and, come event/race day, I want to be used to a helmet and have its fine adjustments sorted) 

2. out of the loads of potential rows I could have with my wife, this is one that’s easy to avoid.

I’d feel much more strongly about it if we had the kind of regulatory incompetence that Australia/NSW seems to be suffering from at the moment, but I just shrug my shoulders at the moment.

[Bez]

FWIW:

FWIW:

https://twitter.com/ianwalker/status/745606048652865537

[ydrol]

I dont think a helment

I dont think a helmet protects you that much. My partner will give me grief if I leave home without it. 

I have had two falls in about 25 years. I think helmet helped on one (cant be sure of course):

 – Fall 1 was due to drafting a vehicle and dropping into a crack/pothole (shoulder took most impact ),

– Fall 2 was turning slowly on a down-ramp covered with soapy water (banged head hard – was dizzy when I got up).

Both incidents were really due to bad cycling and arguably narrow “racer” wheels. So I think my road safely is improved with sensible cycling and running fatter tyres. I run 37mm now.  I continue to use the same 17 year old helmet as foam is not compressed, and I cant be arsed to buy a new one. If its really warm I take it off and hang it on the handlebars. I’m not sure what this all means..

[Author]

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